HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Murondoti, A. Articles by Geelen, M. J. H. Search for Related Content PubMed PubMed Citation Articles by Murondoti, A. Articles by Geelen, M. J. H.

Unrestricted Feed Intake During the Dry Period Impairs the Postpartum Oxidation and Synthesis of Fatty Acids in the Liver of Dairy Cows

¹ Laboratory of Veterinary Biochemistry,
² Department of Farm Animal Health and
³ Department of Nutrition, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
⁴ Department of Clinical Veterinary Studies, Faculty of Veterinary Science, University of Zimbabwe, Harare, Zimbabwe

Corresponding author: M. J. H. Geelen; e-mail: m.j.h.geleen{at}vet.uu.nl.

The purpose of this study was to determine the activities of key hepatic enzymes of fatty acid synthesis and oxidation in cows that had excessive body fat at parturition. Dairy cows were allocated to either an experimental group or a control group. All cows were offered a total mixed ration with an energy content of 6.6 MJ of net energy for lactation per kilogram of dry matter and consisting of corn silage, beet pulp, rapeseed meal, and soybean meal. Control cows were restricted to 6.8 kg/dry matter of the mixed ration in the dry period. Experimental cows had unrestricted access to the mixed ration during the dry period to increase body fat and induce fatty liver postpartum. Blood and liver samples were collected 1 wk before and 1, 2, and 4 wk after parturition. Before parturition, neither the serum nonesterified fatty acids nor the hepatic triacylglycerol concentrations differed between experimental and control cows. After parturition, the values for these variables were greater in experimental cows than in control cows. Plasma 3-hydroxybutyrate increased sharply after parturition in the experimental group. In liver, the activity of acetyl-CoA carboxylase was already significantly lower in the experimental group before parturition. After parturition, the activities of acetyl-CoA carboxylase and fatty acid synthase dropped in the experimental group. The activity of 3-hydroxy-acyl-CoA dehydrogenase in liver was less in experimental cows following parturition. Hepatic citrate synthase activity increased only in the control group after parturition. Unrestricted feed intake before parturition reduces de novo fatty acid synthesis as well as fatty acid oxidation after parturition. The reduction in fatty acid oxidation following parturition may contribute to postpartum accumulation of triacylglycerol in the livers of cows with unrestricted access to feed during the dry period.

Key Words: dairy cow • de novo fatty acid synthesis • fatty acid oxidation • fatty liver

Abbreviation key: ACC = acetyl-CoA carboxylase, CS = citrate synthase, FAS = fatty acid synthase, 3-HAD = 3-hydroxy-acyl-CoA dehydrogenase, NEB = negative energy balance, TAG = triacylglycerol(s)

This article has been cited by other articles:

				J. B. Andersen, C. Ridder, and T. Larsen Priming the Cow for Mobilization in the Periparturient Period: Effects of Supplementing the Dry Cow with Saturated Fat or Linseed J Dairy Sci, March 1, 2008; 91(3): 1029 - 1043. [Abstract] [Full Text] [PDF]

				S. Hachenberg, C. Weinkauf, S. Hiss, and H. Sauerwein Evaluation of classification modes potentially suitable to identify metabolic stress in healthy dairy cows during the peripartal period J Anim Sci, August 1, 2007; 85(8): 1923 - 1932. [Abstract] [Full Text] [PDF]